Why do organisms at the lower level struggle less that organisms above them?

Is it considered muscle s ennervation if sympathetic fibers innervate the vessels within the muscle?

Fan egg cell containing the (n+1) number of chromosomes combines with a sperm cell containing the (n) number of chromosomes, what is the result of this union? a) all future somatic cells of the organism will contain the (2n + 1) number of chromosomes. b) all future somatic cells of the organism will contain the (2n - 1) number of chromosomes. c) only certain somatic cells of the organism will contain the (2n + 1) number of chromosomes. d) all future somatic cells of the organism will contain the normal diploid number of chromosomes.

As a small change in a person's dna can cause a genetic disorder